I. Field of the Invention
The present invention relates to medical devices and methods generally aimed at surgical implants. In particular, the disclosed system and associated methods are related to a manner of creating surgical implants via embroidery.
II. Discussion of the Prior Art
Embroidered structures are created on substrates. Some substrates are designed to stay in place with the embroidered structure while other substrates are removed at the end of the embroidery process. All of the embroidered structures discussed below are created on removable substrates, specifically ones removed through processes of dissolution.
On a dissolvable substrate, a plurality of parallel, stationary backing threads are placed and secured on one surface of a dissolvable substrate, called the backing surface. On the opposing surface of the substrate, called the stitching surface, is a plurality of stitching threads with one-to-one correspondence to the backing threads. Stitching may be done between one pair of threads at a time or in simultaneous multiplicity, as is described below.
The plurality of stitching threads from the stitching surface are passed through openings created in the dissolvable substrate by the passing of each individual thread to the backing surface. Each stitching thread is then looped over its corresponding backing thread, in essence picking up the backing thread, forming a lock stitch. Once each stitching thread has picked up its corresponding backing thread, the plurality of stitching threads are passed from the backing surface to the stitching surface through the openings in the dissolvable substrate created during the passage to the backing surface. The lock stitches prevent the stitching threads from completely pulling back out of the openings created in the dissolvable substrate. The plurality of stitching threads is then moved to a new stitching site and the process repeats until all the backing threads are joined by lock stitches to the corresponding stitching threads, creating a plurality of thread pairs.
A plurality of thread pairs may be enclosed by one or more pluralities of enclosing thread pairs. To enclose a plurality of thread pairs, a plurality of enclosing backing threads are placed and secured on the backing surface of a dissolvable substrate already holding at least one plurality of thread pairs, such that the plurality of enclosing backing threads covers the previously stitched plurality of backing threads. A plurality of enclosing backing threads is usually not parallel with the previous plurality of backing and stitching threads. A plurality of enclosing stitching threads, with one-to-one correspondence to the plurality of enclosing backing threads, are then stitched to the plurality of enclosing backing threads by the stitching process described above.
When the enclosing backing threads are all joined to the enclosing stitching threads by lock stitches, a plurality of enclosing thread pairs has been formed. This process may be repeated by stitching even more pluralities of enclosing thread pairs over all the previously stitched thread pairs, such that the first plurality is enclosed by the second plurality, which is enclosed by a third plurality, which is enclosed by a fourth plurality, etc. This process produces stable embroidered structures which do not unstitch into a pile of threads when the dissolvable substrate is removed.
The process of dissolvable substrate removal is dependent upon the composition of the dissolvable substrate material. Substrate materials are chosen such that the dissolution process which removes the dissolvable substrate will minimally, if at all, affect the physical properties of the remaining embroidered structure. The embroidered structure remains intact despite the removal of the dissolvable substrate because each stitching thread is stitched to its corresponding backing thread and vice versa. The backing thread is enclosed in one or more pluralities of enclosing thread pairs, which provides structural support. The result of the stitching is the creation of a generally two dimensional embroidered structure. There are, however, applications where it would be advantageous to have a generally three-dimensional embroidered structure rather than a generally two-dimensional embroidered structure, but the processes by which three-dimensional embroidered structures may be formed have been complicated and not conducive to cost effective and repeatable mass production.
The first type of process for creating three-dimensional embroidered structures has been to build up the structural shape of the embroidered structure with layer upon layer of embroidered thread. The drawbacks to this technique are that it makes the embroidered structure thicker where the building up had been done. The building up only yields block-type structures and does not allow for the embroidering of curvatures.
A second process of manufacturing three-dimensional embroidered structures takes two or more generally flat embroidered structures and stitches them together such that they form a three-dimensional structure. While preserving the uniform thickness of the embroidered structures lost by the layering technique above and allowing for the simplicity of embroidering each flat section in two-dimensions, this process requires several stitching steps, that would typically be performed manually, which must be done three-dimensionally after the embroidering of the sections is completed. This process is costly, with repeatability concerns where the final results and dimensions will be subject to the skill and dexterity of the individual who performs the stitching.
A third known process creates a single, generally two-dimensional embroidered structure which may be folded such that the edge or edges of the structure meet and may be stitched together, again typically by a manual process, to form a three-dimensional structure. However, this process suffers from the same post-embroidering stitching steps in three-dimensions as the second process, and thus suffers from the same drawbacks.
The present invention is intended to deal with these and other limitations of creating three-dimensional embroidered structures cost effectively and repeatably.